Making an appearance on the ESPN telecast of the Mavs’ Las Vegas Summer League game against Phoenix on Sunday, Cuban said things would different if his team — coming off its first losing season since he took over in 2000 — were in the Eastern Conference. “We’re rebuilding, there’s no question about it,” said Cuban, who made headlines in May when he admitted the Mavericks tanked after being eliminated from playoff contention. “If we were in the East, we would not be rebuilding. We’d be handling things completely different.”